Buggy code:
public class ListDAO extends DAO { private static String ADD_LIST = "INSERT<seq2seq4repair_space>INTO<seq2seq4repair_space>List<seq2seq4repair_space>(name,<seq2seq4repair_space>category,<seq2seq4repair_space>description,<seq2seq4repair_space>username)<seq2seq4repair_space>VALUES<seq2seq4repair_space>(?,<seq2seq4repair_space>?,<seq2seq4repair_space>?,<seq2seq4repair_space>?)" ; private static String EDIT_LIST = "UPDATE<seq2seq4repair_space>List<seq2seq4repair_space>SET<seq2seq4repair_space>name<seq2seq4repair_space>=<seq2seq4repair_space>?,<seq2seq4repair_space>category<seq2seq4repair_space>=<seq2seq4repair_space>?,<seq2seq4repair_space>description<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>WHERE<seq2seq4repair_space>listId<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>AND<seq2seq4repair_space>username<seq2seq4repair_space>=<seq2seq4repair_space>?" ; private static String REMOVE_LIST = "DELETE<seq2seq4repair_space>FROM<seq2seq4repair_space>List<seq2seq4repair_space>WHERE<seq2seq4repair_space>listId<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>AND<seq2seq4repair_space>username<seq2seq4repair_space>=<seq2seq4repair_space>?" ; private static String SUBSCRIBE_LIST = "INSERT<seq2seq4repair_space>INTO<seq2seq4repair_space>Subscription(username,listId)<seq2seq4repair_space>VALUES<seq2seq4repair_space>(?,?)" ; private static String UNSUBSCRIBE_LIST = "DELETE<seq2seq4repair_space>FROM<seq2seq4repair_space>Subscription<seq2seq4repair_space>WHERE<seq2seq4repair_space>username<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>AND<seq2seq4repair_space>listId<seq2seq4repair_space>=<seq2seq4repair_space>?" ; private static String QUERY_LIST_INFO = "SELECT<seq2seq4repair_space>L.listId,<seq2seq4repair_space>L.name,<seq2seq4repair_space>L.category,<seq2seq4repair_space>L.description,<seq2seq4repair_space>L.username,<seq2seq4repair_space>LA.average,<seq2seq4repair_space>COALESCE(C.numcom,0)<seq2seq4repair_space>AS<seq2seq4repair_space>numcom,<seq2seq4repair_space>NOT<seq2seq4repair_space>ISNULL(S.username)<seq2seq4repair_space>AS<seq2seq4repair_space>subscribed<seq2seq4repair_space>FROM<seq2seq4repair_space>List<seq2seq4repair_space>L<seq2seq4repair_space>INNER<seq2seq4repair_space>JOIN<seq2seq4repair_space>List_avg<seq2seq4repair_space>LA<seq2seq4repair_space>ON<seq2seq4repair_space>L.listId<seq2seq4repair_space>=<seq2seq4repair_space>LA.listId<seq2seq4repair_space>LEFT<seq2seq4repair_space>OUTER<seq2seq4repair_space>JOIN<seq2seq4repair_space>(<seq2seq4repair_space>SELECT<seq2seq4repair_space>listId,<seq2seq4repair_space>COUNT(*)<seq2seq4repair_space>AS<seq2seq4repair_space>numcom<seq2seq4repair_space>FROM<seq2seq4repair_space>Comment<seq2seq4repair_space>)<seq2seq4repair_space>C<seq2seq4repair_space>ON<seq2seq4repair_space>L.listId<seq2seq4repair_space>=<seq2seq4repair_space>C.listId<seq2seq4repair_space>LEFT<seq2seq4repair_space>OUTER<seq2seq4repair_space>JOIN<seq2seq4repair_space>(<seq2seq4repair_space>SELECT<seq2seq4repair_space>listId,<seq2seq4repair_space>username<seq2seq4repair_space>FROM<seq2seq4repair_space>Subscription<seq2seq4repair_space>WHERE<seq2seq4repair_space>username<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>)<seq2seq4repair_space>S<seq2seq4repair_space>ON<seq2seq4repair_space>L.listId<seq2seq4repair_space>=<seq2seq4repair_space>S.listId<seq2seq4repair_space>WHERE<seq2seq4repair_space>L.listId<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>ORDER<seq2seq4repair_space>BY<seq2seq4repair_space>LA.average<seq2seq4repair_space>DESC" ; private static String QUERY_LISTS = "SELECT<seq2seq4repair_space>L.listId,<seq2seq4repair_space>L.name,<seq2seq4repair_space>L.category,<seq2seq4repair_space>L.username,<seq2seq4repair_space>LA.average,<seq2seq4repair_space>COALESCE(C.numcom,0)<seq2seq4repair_space>AS<seq2seq4repair_space>numcom,<seq2seq4repair_space>NOT<seq2seq4repair_space>ISNULL(S.username)<seq2seq4repair_space>AS<seq2seq4repair_space>subscribed<seq2seq4repair_space>FROM<seq2seq4repair_space>List<seq2seq4repair_space>L<seq2seq4repair_space>INNER<seq2seq4repair_space>JOIN<seq2seq4repair_space>List_avg<seq2seq4repair_space>LA<seq2seq4repair_space>ON<seq2seq4repair_space>L.listId<seq2seq4repair_space>=<seq2seq4repair_space>LA.listId<seq2seq4repair_space>LEFT<seq2seq4repair_space>OUTER<seq2seq4repair_space>JOIN<seq2seq4repair_space>(<seq2seq4repair_space>SELECT<seq2seq4repair_space>listId,<seq2seq4repair_space>COUNT(*)<seq2seq4repair_space>AS<seq2seq4repair_space>numcom<seq2seq4repair_space>FROM<seq2seq4repair_space>Comment<seq2seq4repair_space>GROUP<seq2seq4repair_space>BY<seq2seq4repair_space>listId<seq2seq4repair_space>)<seq2seq4repair_space>C<seq2seq4repair_space>ON<seq2seq4repair_space>L.listId<seq2seq4repair_space>=<seq2seq4repair_space>C.listId<seq2seq4repair_space>LEFT<seq2seq4repair_space>OUTER<seq2seq4repair_space>JOIN<seq2seq4repair_space>(<seq2seq4repair_space>SELECT<seq2seq4repair_space>listId,<seq2seq4repair_space>username<seq2seq4repair_space>FROM<seq2seq4repair_space>Subscription<seq2seq4repair_space>WHERE<seq2seq4repair_space>username<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>)<seq2seq4repair_space>S<seq2seq4repair_space>ON<seq2seq4repair_space>L.listId<seq2seq4repair_space>=<seq2seq4repair_space>S.listId" ; private static String QUERY_LISTS_BY_CREATOR = ( ListDAO . QUERY_LISTS ) + "<seq2seq4repair_space>WHERE<seq2seq4repair_space>L.username<seq2seq4repair_space>=<seq2seq4repair_space>?<seq2seq4repair_space>ORDER<seq2seq4repair_space>BY<seq2seq4repair_space>LA.average<seq2seq4repair_space>DESC" ; private static String QUERY_LISTS_BY_SUBSCRIBED = ( ListDAO . QUERY_LISTS ) + "<seq2seq4repair_space>WHERE<seq2seq4repair_space>S.username<seq2seq4repair_space>IS<seq2seq4repair_space>NOT<seq2seq4repair_space>NULL<seq2seq4repair_space>ORDER<seq2seq4repair_space>BY<seq2seq4repair_space>LA.average<seq2seq4repair_space>DESC" ; private static String QUERY_LISTS_BY_CATEGORY = ( ListDAO . QUERY_LISTS ) + "<seq2seq4repair_space>WHERE<seq2seq4repair_space>L.category<seq2seq4repair_space>LIKE<seq2seq4repair_space>?<seq2seq4repair_space>ORDER<seq2seq4repair_space>BY<seq2seq4repair_space>LA.average<seq2seq4repair_space>DESC" ; private static String QUERY_LISTS_BY_KEYWORD = ( ListDAO . QUERY_LISTS ) + "<seq2seq4repair_space>WHERE<seq2seq4repair_space>L.name<seq2seq4repair_space>LIKE<seq2seq4repair_space>'%?%'<seq2seq4repair_space>ORDER<seq2seq4repair_space>BY<seq2seq4repair_space>LA.average<seq2seq4repair_space>DESC" ; public ListDAO ( ) throws ClassNotFoundException , SQLException { } public boolean addList ( List list , User user ) throws SQLException { } public boolean editList ( List list , User user ) throws SQLException { } public boolean removeList ( List list , User user ) throws SQLException { } public boolean subscribeList ( List list , User user ) throws SQLException { } public boolean unsubscribeList ( List list , User user ) throws SQLException { } public ArrayList < List > findByCreator ( User creator , User user ) throws SQLException { } public ArrayList < List > findBySubscribed ( User user ) throws SQLException { } public ArrayList < List > findByCategory ( String category , User user ) throws SQLException { } public ArrayList < List > findByKeyword ( String keyword , User user ) throws SQLException { } public List findById ( List list , User user ) throws SQLException { <START_BUG> PreparedStatement ps = con . prepareStatement ( QUERY_LISTS_INFO ) ; <END_BUG> ps . setString ( 1 , user . getUsername ( ) ) ; ps . setInt ( 2 , list . getId ( ) ) ; ArrayList < List > lists = this . parseResultSet ( ps . executeQuery ( ) ) ; ps . close ( ) ; return lists . get ( 0 ) ; } private ArrayList < List > parseResultSet ( ResultSet rs ) throws SQLException { } private ArrayList < List > parseResultSetDisplay ( ResultSet rs ) throws SQLException { } }

Fix:
PreparedStatement ps = con . prepareStatement ( ListDAO . QUERY_LIST_INFO ) ;